Acetaminophen (APAP) is a well-known analgesic and antipyretic drug. In the United States, it is available for non-prescription over-the-counter sale in conventional liquid, suppository, capsule, tablet and caplet dosage forms. The tablet and caplet dosage forms typically contain 325 mg acetaminophen as "regular strength" or 500 mg as "extra strength". Normally, regular strength tablets or caplets are taken as one or two every four hours, and the extra strength tablets or caplets are taken as one or two every six hours. Ideally, it would be desirable to extend th dosing interval while maintaining the initial plasma concentrations achievable with conventional tablets or caplets. This would provide immediate and extended therapeutic analgesic or antipyretic effect and reduce the number of doses necessary, thereby making therapy more convenient. A way to do this has now been found, using the present invention, whereby two tablets or caplets each containing 650 mg acetaminophen can be formulated to provide both immediate release and sustained release or sustained release alone such that the dosing interval can be extended to at least eight (8) hours. In addition, the quantity (amount) of the sustained release matrix can be adjusted up or down to produce tablets for sustained release that have more or less than 650 mg of acetaminophen. For example, a tablet containing 500 mg of acetaminophen can be manufactured from the same composition by simply decreasing the size and weight of the final tablet by a multiple of 10/13. The present invention can be used to obtain any desired sustained release acetaminophen tablets of different dosages, e.g. a 500 mg sustained release tablet which results in lower blood plasma levels over eight hours, than with the 650 mg tablet, and desired longer or shorter time periods, e.g. twelve hours are possible. From a practical standpoint eight (8) hours might be the most desired interval. The matrix of the present invention can be used to make acetaminophen sustained release pharmaceutical preparations in compressed tablet form. The matrix materials used are compressed into a shaped tablet form. The term "tablet" as used herein includes tablets of any shape, and includes caplets, which are tablets having a capsule shape. The tablets may be coated with a pharmaceutically acceptable coating material or have pharmaceutically acceptable coloring added to the composition prior to compression.